Car coupler



June 28, 1966 w, METZGER ET AL 3,258,132

CAR COUPLER S Sheets-Sheet 1 LOCK SET Filed April 1, 1965 COUPLED ally? I L a WW WW #5 UNCOUPLED v! E MMZ O o m m 5w WHZ A mmpp Mi Z Y B 4. 1

June 28, 1966 w, M T ET AL 3,258,132

CAR COUPLER 5 Sheets-Sheet 2 FULLY RETRACTED 2 Filed April 1, 1965 INVERTED 5 w 25% T255 0 $21 v A m Ju June 28, 1966 w. J. METZGER ET AL 3,258,132

CAR COUPLER 5 Sheets-Sheet 5 Filed April 1, 1965 INVENTORS Y K M Hf? M? A if Mi xp B United States Patent 3,258,132 CAR COUPLER William .I. Metzger, East Cleveland, Kenneth L. De Penti, Mayfield Heights, and Dennis E. Dawson, Highland Heights, @hio, assignors, by mesne assignments, to Midland-Ross Corporation, Cleveland, @hio, a corporation of Ohio Filed Apr. 1, 1965, Ser. No. 444,672

' 18 Claims. ((11. 2131tlll) This invention relates to car couplers of the rigid jaw type which have a lock pivoted in a lower rear wall portion of the coupler head and have mechanism providing anti-creep protection and adjustment to a lock-set condition. Earlier couplers of this general type are disclosed in United States Patents No. 2,591,275 and No. 3,033,385 issued to one of the present applicants, William I. Metzger. The improvements of this general type of coupler as herein described are concerned with maintaining positive coupling regardless of 'the position of the coupler, improved anti-creep protection, and reduced vertical dimension of the coupler head.

Hence, an important object of the invention is to provide a fixed-jaw coupler having improvements of mechanism which assure maintenance of the coupler in a locked condition in the inverted position and tend to prevent accidental displacement of the lock resulting from severe jolting or relative movement of intercoup'led couplers.

It is also an important object to achieve fixed-jaw coupler design providing a smaller top-to-bottom dimension than that occurring in conventional couplers of the same general type without significant reduction in the required bearing area on the lock for engaging the lock of an intercoupled coupler.

A further object is to obtain coupler design resulting in good coupler operation through favorable relationships of the centers of gravity of the various movable components, e.g., the lock and the lock-set piece, with respect to respective pivot or fulcrum supports.

Another object is to establish high-torque, frictionless relationship of the lock thrower with the lock in accomplishing the above objects.

Another object is to render the coupler of the foregoing objects. free from fracture of the lock-thrower shaft so that, for example, the shaft is able to stand up under such forces as arise during high speed coupling.

Still another object coincidental with the foregoing objects is to rearrange the rotor mechanism to facilitate assembly of the coupler, easier insertion of the rotor shaft, more freedom to position the external portion of the rotor relative to the head, andgreater freedom to counterweight the rotor externally of the head.

In brief, the above objects are achieved in' a rigid jaw coupler having a head providing a cavity, top wall and a mouth openin toward the front of the coupler, wherein a lock is supported inside the cavity with its lower rearward portion in pivotable relation with the lower rearward portion of the head. The lock, thus being able to swing from a forward coupler-locking position to a rearward unlocking position, has a forward-to-rearward extending slot. Other components of the coupler are a lock-thrower and a shaft therefor which are both rotatable with respect to a transverse axis in such fixed relation with the head as to align the shaft through the slot. While the slot is contoured to accommodate the shaft in all operational positions of the lock, the shaft occupies a rearward portion of the slot in the locking position of the lock. in order to trap the lock in its locked position, should the lock move toward the top wall, as, e.g., during inversion of a car or a violent upward jolt of the coupler, the rearward portion of the slot is enlarged by a downwardly-extending recess shaped to receive at least a portion of the shaft as a result of any displacement of the lock toward the top wall of the head.

To further assure that the lock will be retained in its locking position, though displaced from its seat in the lower part of the cavity toward the top wall, the undersurface of the top wall and the top surface of the lock define forward-facing and rearward-facing shoulders, respectively, which pass into confronting relationship in -a movement of the lock toward the top wall disposing any portion of the shaft in the recess.

When the lock comprises a signal fin projecting from a lower rearward surface, the coupler head has an aperture in its rear wall providing for passage of the fin therethrough in rearward movement of the lock out of locking position. However, the fin is contained within thehead cavity to an extent permitting movement of the lock from its forwardmost position toward the top wall without interference with the rear wall.

In a preferred embodiment, side walls of the head define bearings for the shaft of which the bearing in the side wall contiguous with the pulling jaw is larger than that in the side wall connected with the bufiing jaw, there by limiting insertion of the rotor shaft into the head from the pulling jaw side of the coupler. Disposed inwardly of the head between the two bearings is a support lug contiguous with the rear wall terminating adjacent the region occupied by the hub of a thrower carried on the rotor shaft. The front surface of the lug is related with the internal periphery of the bearings so as to support the thrower hub and to thus avoid substantial shock loading of the shaft and bearing surfaces.

' In the following detailed description of the invention:

FIGS. 1, 2, 5, 6, 7 and 8 are side elevations in section illustrating the coupler mechanism in the various positions identified by the title of the figures. The plane of section is taken along the inner surface of the foreground side wall, the effect being to eliminate from these figures the side wall of the coupler head that is contiguous with its pulling jaw. Also eliminated by this mode of sectioning is a vertical Wall along the front of the coupler head cavity on the foreground side of the lock.

FIG. 3 is a fragmentary elevation in section of the coupler as taken along line IIIIII of FIG. 6.

FIG. 4 is a plan view in section with the coupler .components shown in position corresponding to those illustrated by FIG. 5 but with portions of the coupler head removed to a horizontal plane passing through the rotor axis.

FIG. 9 illustrates the lock included in FIGS. 1 to 8 in an upper plan view and a lower side elevation.

FIG. 10 comprises side elevation and end views of a thrower adapted to be assembled with the rotor shaft of FIGS. 13 to 15.

FIG. 11 consists of a side elevation view at the left and an end view at the right of an anti-creep element normally mounted on an integral trunnion of the coupler head.

FIG. 12 illustrates by an upper plan view and a lower side elevation a lock-set piece supported during operation on the trunnion shown in FIGS. 1 to 8 for supporting the anti-creep element of FIG. 11.

FIG. 13 is a shortened longitudinal view of a rotor shaft for carrying the thrower of FIG. 10.

FIG. 14 is a transaxial section of the rotor shaft taken along line XIVXIV of FIG. 13.

FIG. 15 is a transaxial section of the rotor shaft taken along line XV-XV of FIG. 13.

Considering the invention as embodied in a fixed jaw coupler 5 in more detail, components of the coupler will be observed in FIGS. 1 to '8 to comprise a head 6 having a cavity 3 which opens frontwardly in a mouth 4, a shank 7 integral with the head and extending rearwardly'therefrom, a lock 8 pivoted within the cavity relative to the head by a lower rearward portion thereof forming a pivotal joint with a lower rearward portion of the head, a lock-throwing rotor 9 comprising a thrower cam 9a and a shaft 9b, a lock-set piece 10 pivotally mounted in the head 6 on a trunnion 11 integral therewith, and an anticreep element 12 pivotally mounted on the trunnion 11 with its front portion resting on an upward facing surface of the lock-set piece 10.

In FIG. 1, a lock 8 is shown in its forwardmost and locking position within the cavity of the head 6 wherein the lock is seated on the bottom wall 15 partly by contact of its undersurface 16 with a forward upward-facing surface 17 of the bottom wall and also by engagement of proximal areas of a tooth 18 of the lock with a front shoulder 21 and a rear shoulder 22. These shoulders are disposed within the cavity at the upper entrance of an opening 23 extending downwardly and rearwardly through the lower rear portion or bottom wall 15 of the head. The lock 8 occupies a similar position relative to the head in its uncoupled (FIG. 5) position.

In connection with the present invention, it should be noted that the rear surface 25 of the tooth 18 extends in an approximately vertical directiontoward the base of a rearward-extending tooth 26 so that the tooth 18 does not impede movement of the lock under certain conditions toward the top wall 27 of the head. The vertical length of the tooth 18, as measured along the rear surface 25, exceeds an overhead clearance 28 as measured between the upper rear corner 29 of the lock and a point 31 along the undersurface 32 of the top wall 27. Point 31 also marks the upper extremity of a front-facing shoulder surface 33 extending downwardly from the surface 32 as a front side of a sawtooth shaped shoulder 34 protruding from the undersurface.

The teeth 18 and 26 together form a bifurcation at the lower rear extremity of the lock which protrudes slightly laterally to define a surface 39. This surface, along with a similarly laterally raised surface of the front portion of the lock, function as bearing surfaces which engage the side wall 37. Their purpose is to minimize the effort required to shift the lock from one position to another by minimizing the surface of the lock in frictional contact with the wall 37.

The lock is provided with a rearward-facing shoulder 36 formed by a recess including approximately one-half the thickness of the lock. This recess is located in the corner portion 29 of the lock adjacent the side wall 37 of the head that is contiguous with its butting jaw 38. The purpose of the shoulders 33 and 36 is that they move into confronting relationship as the lock moves in a direction toward the top wall 27 through the clearance 28. Such movement of the lock may result from inversion of the coupler occurring, e.g., during the overturning and the dumping of a coal or ore carrying car, or during violent impacting of the coupler tending to thrust it in an upward direction. The shoulder surfaces 33 and 36 are intended to engage under such conditions to prevent its movement out of locking engagement with the lock of another coupler intercoupled with its associated coupler. Such engagement is shown in FIG. 7 wherein the various components are shown in the position assumed as if the coupler was inverted with respect to the typically upright positions of FIGS. '5, 6, and 8.

As a further feature of this invention, the movement of the lock to the position shown in FIG. 7 is made possible by a recess 41 constituted of a downward concave enlargement of the rear portion of a slot 42 through which the rotor shaft 9b extends in a horizontal transverse direction. The slot may be generally arcuate as shown and concentric to the pivotal connection of the lock with the lower rear portion of the head, and of a length to accommodate the shaft at all operating positions of the lock.

However, to attain the position of FIG. 7, the shaft 9b moves into the recess 41 as the shoulder surfaces 33 and 36 pass into confronting or engaged relationship. In this condition of the coupler, the lock is stopped with the tooth surface 25 against the shoulder 22, a forward area 43 of the recess 41 against the shaft 9b, and the lock shoulder surface 33 bearing on the shoulder surface 36 of the head 6.

The lock is preferably provided with a signal fin 45, shown in FIG. 4 in longitudinal alignment with an aperture 46 extending through the rear wall 47 of the head 6. The fin 45 is thus in alignment with a longitudinal portion of the lock adjacent to the side wall '37 and also in longitudinal alignment with the shoulder 36 and an area 51 along the upper forward portion of the lock. The area 51 is related with respect to the adjacent surface to enable the lock to pass under the shoulder 34 in reaching a fully retracted position such as shown in FIG. 6.

FIG. 6 also illustrates that the fin 45 has an indicium, such as the hole 52, which, in the fully retracted position of the lock, becomes disposed exteriorly of the opening 46 and the wall 47 so as to be readily visible. The fully retracted position is that assumed during the practice known as neutralizing the coupler. A neutralized condition is conventionally attained by an operating mechanism (not shown) which may comprise stops located, e.g., on the car body, for holding the lock fully retracted and in a condition wherein the coupler will enable one car to push another without intercoupling and be separable afterwards. As shown by FIGS. 1, 5, and 7, the fin 45 is of a length enabling it to be wholly withdrawn into the head cavity, and at least forwardly of that portion of the inner-surface of the Wall 47 disposed immediately above the aperture 46. Such limitation in the length of the fin enables it to be carried by the lock upwardly and interiorly of the coupler head but frontwardly of the wall 47 and above or partially above the opening 46.

Another improvement of the presently described coupler resides in construction by which the rotor shaft may be inserted into the head from the side thereof which the pulling jaw 55 is disposed. Accordingly, the side wall 56 of the head contiguous with pulling jaw 55 comprises a bearing 57 which is of larger diameter than the aperture portion or bearing 58 of the opposite side wall 37. The bearings 57, 58 receive journals 6 1 and 62, respectively, of the rotor shaft 9b. As shown, the head 6 further comprises a support portion 64 having an outboard bearing 65 for supporting another journal 66 of the shaft 9b. The inner diameter of the bearing 65 is at least as large as that of the bearing 61 in order that the rotor shaft may be fully insertable into operating position.

The length of the coupler head, as shown, is governed somewhat by the desired external relationships of the coupler with other portions of a car draft rigging, and also by the space needed for movement of internal components of the coupler. The lock 8 is designed with the proportions shown, particularly with a minimum frontto-rear dimension along its top portion, in order to establish its center of gravity as forwardly as possible with respect to its pivotal connection with the head. This facilitates return of the lock by gravity to its forwardmost position. Hence, as the upper portion of the head is somewhat longer than necessary to accommodate the lock in its fully retracted position which disposes the lock in for-ward spaced relationship with respect to the upper portion of the rear wall 47, the head includes a stop lug 7 1 in the coupler rear corner of the head integral with, and extending forwardly from the wall 47 in longitudinal alignment with the lock.

The lock-set piece 10, on the other hand, depends upon disposition of its center of gravity rearwardly of its pivotal support, i.e., the trunnion 11, for good positionb ing in clockwise rotated positions, such as shown in FIGS. and 6, and in the positions illustrated, e.g., in FIGS. 1 and 2, typical of its positioning as when its sensing pad 73 is engaged by another coupler coupled with its parent coupler.

Various figures of the drawing illustrate that the pad 73 of the clock-set piece comprises a fiat lug 72 extending rearwardly from a lower portion of the lateral edge of the pad nearer the lock. This lug is thin in the transverse direction of the coupler and relatively wide in the vertical and longitudinal directions of the coupler.

In prior art couplers of the general type to which this invention relates, the lock-set piece has been constructed without any equivalent of the lugs '72, and thus coupled couplers have occasionally failed to uncouple. Such failure happens as the result of lateral shifting of a pad (constructed without a lug) of the lock-set piece when the coupler is in lock-set condition and an attempt is made to uncouple. At this instant, the lock-set piece may pivot sideways to place a portion of the pad in front of the lock. As a consequence, the entrance to the pocket within the pulling jaw occupied by the buffing jaw of the opposing coupler, during coupled condition, is reduced to an extent making withdrawal of the opposed buffing jaw impossible.

As shown in the plan view of FIG. 12, the lug 72 is in flush relation with the general lateral contour of the lock-set piece 110. It is of a length in the rearward direction of the coupler, to enable itto engage the nearer side of the lock 8, if need be, at such rearward position of the lock as to prevent sidewise shifting of the pad to a position partially in front of the lock. In this manner, uncoupling action is made more positive.

In order to obtain nearly maximum rearward disposition of the center of gravity of the lock-set piece 6, the portion of the lock-set piece rearwardly of the trunnion 11 extends nearly the full length of the upper portion of the head cavity adjacent the top wall 27. The rear portion 74 of the lock-set piece may be considered in the nature of a counterweight since it is constructed of a horizontal thickness which occupies that portion of the horizontal transverse dimension of the head cavity not occupied by the lock. That is to say, in the upper cavity portion, the thicknesses of the lock and the lock-set piece in side-by-side relationship nearly equal the Width of the cavity, as shown in FIG. 4.

The lock 8 and lock set piece 10 are actuated by the thrower 9a which comprises a lock actuating cam 75 and a cam 76 for actuating the lock-set piece in camfollower relation with cam-following surfaces 77 and 78 of the lock 8 and the lock-set piece 18, respectively. Retraction of the lock is effected primarily through contact of the cam surface portion 81 of the thrower with a rear, steeply-inclined following surface 82, as illustrated by FIGS. 2, 6, 7, and 8, and is accomplished during clockwise rotor movement in respect to these figures.

During operation, the thrower 9a is confined between the side wall 56 of the head and a thin vertical section 80 of the lock constituting the back wall for the recess for receiving the cam 75 and having as its periphery the cam-following surface 77. The thrower 9a is supported on shaft portion 83 of out-of-round cross section approximating a half-circle joined with a halfsquare. This portion of the shaft is received in a hub portion 84 of the thrower having an aperture 85 complementary to the shaft portion 83.

When the thrower 9a is supported on the shaft 91) as shown in various figures, its usual neutral position is that shown in FIGS. 1 and 5, wherein the cams 75, 76 project generally horizontally forwardly from the axis of the rotor shaft with a limit lug 88 which projects outwardly from the hub 84 of the thrower. In neutral position, the lug 88 engages the underside 89a of an abutment rib 89 integral with the rear wall 47 and the side wall 56 which extends into such close proximity with the surface of the hub 84 as to support the hub when subjected to a substantial rearward directed force on the thrower without transmitting any substantial portion of that force to the rotor shaft 9b. The thrower is occasionally subjected to substantial shock ,forces in the rearward longitudinal direction of the coupler during, e.g., coupling of cars at high-coupling speeds. It is on such occasions that the lock is impacted backwardly with considerable force. Its convex follower surface portion 91 is caused to' engage a concave surface portion 92 of the lock-thrower cam 75.

The anti-creep element 12 functions in a manner known to the prior art, for example, in Metzger Patent Nos. 2,591,275 and 3,033,385. This element has a bore 95 for receiving the head trunnion Ill for establishing pivotal connection therewith allowing the element 12 to pivot as the result of resting on the lock-set piece 10 during its movements. The lock-set piece has an upward extending slot 96 of a width adapting it to receive the trunnion 11 whereby guide relationship is established between the lock-set piece and the trunnion permitting limited pivotal and linear movement of the lock-set piece relative to the trunnion 11.

The various figures show that a hook portion 97 of the element fits around a small lug 98 on the forward face of the lock-set with an undersurface 97a of the hook portion resting on a shelf surface 99. The anti-creep element terminates forwardly in an abutment surface 101 which, when the coupler is in the condition shown in FIG. 1, is positioned rearwardly and closely to an anti-creep lug 102 projecting sidewise from a portion of the lock having full thickness adjacent to the cam follower surface 77. As is well-known, the purpose of the anti-creep mechanism is to prevent unintended unlatching of the lock with another coupler. The anti-creep abutment 101 is to be engaged by the look lug 102 upon slight movement rearward as long as thelock-set piece 10 is not lifted. However, lifting or a certain amount of clockwise movement of the look-set piece from the position shown in FIG. 1, e.g., see FIG. 5, swings the forward portion of the lockset piece 12. upwardly carrying the abutment 101 out of the swing path of the lug 182, thereby enabling the lock to swing freely to its rearward position. While a tilting movement of the lock-set piece will inactivate the anticreep mechanism, as illustrated by FIG. 5, operation of the rotor entailing lifting of the lock-set piece by the cam 76 and engagement of the cam-following surface 78 also lifts the anti-creep element upward and thus inactivates the anti-creep mechanism as illustrated in FIG. 8.

As a starting point in the operation of the coupler, uncoupled condition may be assumed as illustrated in FIG. 5, wherein the lock is in its forwardmost position, the rotor cams 75, 7e are pointing forwardly, and the lock-set piece 10 has been rotated through its maximum clockwise position under the effect of its own center of gravity. The lock-set piece is stopped in this position by a laterally extending handle 1105 thereof which rests on a lower peripheral surface 106 of an opening 187 in the wall 56. This opening, while located in the wall 56, is shown dotdash in outline in the several views wherein the wall 56 is cut away. As mentioned before, the lock-set piece is raised out of lock holding position when the lock-set piece is free to position as shown in FIG. 5.

During the act of coupling, i.e., in making a transition from the position of FIG. 5 to the coupled position of FIG. 1, the lock 8 will be thrust backward toward the look cam of the rotor and may, in fact, impact this cam if the coupling is rapid. The locks on both intercoupling couplers move rear-ward just enough to allow the locks to pass by each other as the couplers become engaged. The looks then return to the position shown in FIG. 1 or FIG. 5, and while so returning, thebuffing jaw (similar to the jaw 38) and the lock of the opposed coupler move into place against the pad 73 of the lock-set 7 piece and cause the lock-set piece to assume the position shown in FIG. 1.

Getting the coupler out of its locked or coupled condition (FIG. 7) is possible only by performing a manual operation on the coupler. The choices are to rotate the rotor 9 to effect either (1) the look-set condition of FIG. 2, or (2) the fully-retracted condition of FIG. 6. FIG. 8 illustrates the condition of the coupler after partial rotation of the rotor just before lock-set condition is reached. It should be noted that the rotor cams 75 and 76 are both acting on the lock and the lock-set piece, respectively, to lift them away from the positions of FIG. 1. Lifting of the lock is done primarily through engagement of the convex cam surface 81 of the rotor with follower surface portion 82 of the lock. As clockwise rotation of the rotor continues, the corner 111 of the lock-set piece actuating cam 76 passes to the rear of the corner 112 in the cam following surface 78 of the lock-set piece and permits the lock-set piece to drop to a position placing a rearwardfacing portion 114 of the follower-surface 78 in opposing relation with the now front-facing surface 115 of the cam 76.

In this manner a lock-set condition is reached (FIG. 2) wherein the opposing coupler (not shown) remains engaged with the pad 73 to hold the lock-set piece from rotating. The cam 76 now rests against the vertical surface 114 of the lock-set piece and the cam 75 stands against the front facing follower surface 82 of the lock. Because the lock is retracted, the opposing coupler may be readily withdrawn from the coupler, as shown in FIG. 2, whereupon the lock-set piece will rotate clockwise to the position shown in FIG. 5, the rotor will be thereby released to rotate counterclockwise to release the lock, and the lock will drop forward to the position shown in FIG. 5.

Further observance of FIG. 8 will make apparent that retraction of the lock to the partial extent illustrated involves pivoting of the lock about the apex portion of the shoulder 22 engaging the lock at the juncture of teeth 18 and 26. However, as the lock tilts further rearward from this stage, pivoting of the lock with respect to the shoulder 22 occurs at a fulcrum located rearwardly of the shoulder apex at a point 118 on the shelf surface 119 of the shoulder 22, where it is engaged by the rear point of the tooth 26. To attain the fully retracted condition of FIG. 6 involves merely more rotation of the rotor to a position wherein it is held from return rotation by external holding means (not shown) which may be of known design. Because the lock is now resting on a fulcrum 118 at a nearly maximum rearward position within the head 6, its center of gravity is forwardly of this fulcrum to a greater extent than if the lock was pivoted on the shoulder farther frontwardly. This arrangement facilitates a positive return of the lock to locking position when the rotor is released, or the lock-set piece is clockwise rotated to allow release of the lock.

Assuming two couplers to be coupled and one coupler to be in lock-set position, the lock-set coupler may be restored to coupled condition by lifting the look-set piece sufiiciently to disengage the rotor cam 76 from the lock-set piece surface 116. This may be done by lifting on the handle 105.

The cam 76 has an outermost peripheral surface portion 117 disposed between the two adjacent inturned surface portions which is convex and in generally concentric relation to the rotor axis to smooth the return action of the cam as it passes under the corner 112 of the lock-set piece.

This is beneficial in both automatic or manual release of top wall 27 to a maximum extent. Movement of the lock out of locking relation with the lock of an opposed coupler is prevented at three points in a manner already described.

The terms and expressions which have been employed are used as terms of description and not of limitation and there is no intention of excluding such equivalents of the invention described, or of the portions thereof, as fall within the scope of the claims.

What is claimed is:

1. A car coupler comprising:

a rigid-jaw head having a top wall, a cavity, and a mouth for the cavity opening toward the front of the coupler;

a lock supported inside the cavity with the lower rearward portion thereof in pivotable relation with the lower rearward portion of the head enabling the lock to swing from a forward coupler-locking position to a rearward unlocking position, said lock having a forward-to-rear ward extending slot;

a lock thrower and a shaft therefor rotatable with respect to a transverse axis in fixed relation with the head extending through said lock slot, said slot being contoured for accommodating said shaft in all operational positions of the lock and thereby causing the shaft to occupy a rearward portion of the slot when in said locking position;

said rearward portion of the slot being enlarged by a downwardly extending recess adapted to receive a portion of said shaft, and said head providing head clearance between the lock and said top wall permitting such movement of the lock toward said top wall so as to dispose said shaft in said recess.

2. The car coupler of claim 1 wherein:

said top wall has a frontward-facing shoulder accessible to said lock from underneath said wall;

said lock has a top surface and a rearward-facing shoulder disposed in downward, generally opposed relation with said frontward-facing shoulder at said locking position of the lock;

said lock being movable while in locking position toward said top wall to dispose said shoulders in confronting engageable relationship when said shaft becomes disposed in said recess.

3. The car coupler of claim 1 wherein:

said top wall has an undersurfaee and the lock has a top surface and a recess therein defining a rearwardly-facing shoulder disposed in downward, generally opposed relation with respect to said frontward-facing shoulder at said locking position of the lock;

said lock being movable while in locking position toward said top wall to dispose said shoulders in confronting engageable relationship when said shaft becomes disposed in said recess.

4. The car coupler of claim 1 wherein:

said lock has a top surface, and said top wall has an undersurface and a front-facing shoulder projecting downwardly therefrom in, and limited to, vertical alignment with a longitudinally elongate portion of said top surface;

said lock having a rearward-facing shoulder extending downwardly from said top surface portion with its width in a transverse direction of the coupler limited to that of said top surface portion, said top surface portion being relieved and separately contoured with respect to a transversely adjacent coextensive top surface portion to maintain clearance with said frontward-facing shoulder during normal pivotal movements of the lock between said positions thereof;

said lock being movable while in locking position toward said top wall to dispose said shoulders in confronting engageable relationship when said Shaft becomes disposed in said recess.

said lower lock portion comprises a second tooth pro- 9. The car coupler of claim 1 wherein: the head comprises a rear wall and a shank extending said lock has as its rearward extremity a rearward exsaid fin carrying indicia thereon disposed along its 5. The car coupler of claim 1 wherein: said lower rear head portion has a downwardly extending opening; and

said lower lock portion comprises a first tooth extend- 6. The coupler of claim 5 wherein: the rear side of said tooth' is approximately vertical at the locking position of the lock.

7. The coupler of claim 6 wherein: the rear side of said opening is defined by a shoulder of which its upper surface extends rearwardly from the opening; and

jecting rearwardly from the upper extremity of the first tooth and has an undersurface in bearing relation with said shoulder.

8. The coupler of claim 7 wherein: said second tooth is shorter in rearward extent than rearwardly therefrom and the rear wall has an aperture therethrough directly rearward of the path of the lock in moving between said positions; tending signal fin aligned to pass through said aperture in movement of the lock to a rearward position;

said fin being of a length to dispose its rear extremity inwardly with respect to that portion of said rear 10. The car coupler of claim 5 comprising: a lock-set piece pivotally supported alongside said lock with respect to an axis in fixed relation with the head;

said lock thrower having a cam for engaging and operating said lock and a second cam for engaging and operating said lock-set piece; 5

said lock being retractable rearwardly to a lock-set position and further rearwardly to a fully retracted position, adapting the coupler to be placed in a neutralized condition; and length so as to be positioned inwardly of said apertures at all positions except at said fully retracted position of the lock.

11. The car coupler of claim 1 comprising: a lock-set piece pivotally supported alongside said lock with respect to an axis in fixed relation with the head;

said lock thrower having separate cams for actuating said cam for operating the lock-set piece having an outermost peripheral surface portion approximately concentric with the axis of said rotor and disposed between radially inturned surface portions. 12. The car coupler of claim 1 wherein: said head comprises a buffing jaw and a side wall in contiguous rearward relation therewith, and a pulling jaw and a side wall in contiguous rearward relation therewith; said side walls defining bearings for said rotor shaft of which the bearing in the second-named side wall is of larger diameter than that in the first-named side wall; and said rotor shaft is insertable into said head from outboardly of said second-named wall. 13. The coupler of claim 12 wherein: said head comprises an outboard support for said rotor shaft extending outboardly of said second-named wall and defining a bearing for the shaft having a diameter at least as large as said bearing of the secondnamed wall. 14. The car coupler of claim 1 wherein: said thrower comprises a hub receiving said shaft; and said head comprises a rear wall and a supporting rib merging with said rear wall and extending forwardly and generally horizontally therefrom into close proximity with the rearwardmost portion of the perimeter of said hub. '15. The car coupler of claim 1 wherein: said head has a side wall in lateral supporting juxtaposition with said lock; and said lock has a front portion adapted to engage a lock of a similar coupler coupled therewith, and a. lower bifurcation in bearing pivotal relation with a shoulder of said head; and the lateral surface of the lock facing said side wall has portions overlying said front portion and said bifurcation which are raised with respect to the remainder of said lateral surface which slidably engage said side wall. 16. The coupler of claim 1 having structure for minimizing the vertical dimension of said coupler comprising: a lock-set piece pivotally supported alongside said lock with respect to an axis in fixed relation with the head; slip connection means for connecting the lock-set piece to the head in rotatable and linear generally vertical movement relative thereto; said top wall having a flat undersurface extending horizontally forwardly from said rear wall; said lock at said unlocking position having a flat upper longitudinal surface substantially coextensive and parallel with said undersurface adapted for close proximity thereto; said lock-set piece having a fiat upper surface approximately of equal length with said undersurface adapting it for parallel proximity thereto in uppermost operable positions of the lock-set piece. 17. The car coupler of claim 1 wherein: said lower rearward portions of the lock and the head comprise stop means limiting rearward movement of said lower portion of the lock in moving through said head clearance; said lock and said top wall comprise a forward-facing shoulder and a rearward-facing shoulder disposable into confronting relationship as said lock moves through said head clearance; said head comprises a rear wall and a shank extending rearwardly therefrom, the rear wall having an aperture disposed below the shank and in rearward alignment with the path traversed by the lock in moving between said positions thereof; and said lock has a signal fin movable through said aperture and disposed inwardly of the rear wall at said locking position of the lock. 18. The car coupler of claim 1 comprising: a lock-set piece pivotal-1y supported alongside said lock 1 1 1 2 with respect to an axis in fixed relation with the head References Cited by the Examiner and having a forward sensing pad for engaging an opposing coupler when coupled With said coupler; UNITED STATES PATENTS said lock thrower having a cam for engaging and operating said lock and a second cam for engaging and I 9 L275 4/1952 Metzger 213 100 operating said lock-set piece; 3,033,385 5/1962 M ger 2131O0 said pad having a lug extending rearwardly from the lateral edge of the pad nearer the lock and being dis- ARTHUR LA POINT, Primary Examinerposed for guide relationship with the adjacent lateral surface of the lock in all rearward positions thereof. 10 FAUST Asslsmnt Examiner 

1. A CAR COUPLER COMPRISING: RIGID-JAW HEAD HAVING A TOP WALL, A CAVITY, AND A MOUTH FOR THE CAVITY OPENING TOWARD THE FRONT OF THE COUPLER; A LOCK SUPPORTED INSIDE THE CAVITY WITH THE LOWER REARWARD PORTION THEREOF IN PIVOTABLE RELATION WITH THE LOWER REARWARD PORTION OF THE HEAD ENABLING THE LOCK TO SWING FROM A FORWARD COUPLER-LOCKING POSITION TO A REARWARD UNLOCKING POSITION, AND LOCK HAVING A FORWARD-TO-REAR WARD EXENDING SLOT; A LOCK THROWER AND A SHAFT THEREOF ROTATABLE WITH RESPECT TO A TRANSVERSE AXIS IN FIXED RELATION WITH THE HEAD EXTENDNG THROUGH SAID LOCK SLOT, SAID SLOT BEING CONTOURED FOR ACCOMMODATING SAID SHAFT IN ALL OPERATIONAL POSITIONS OF THE LOCK AND THEREBY CAUSING THE SHAFT TO OCCUPY A REARWARD PORTION OF THE SLOT WHEN IN SAID LOCKING POSITION; SAID REARWARD PORTION OF THE SLOT BEING ENLARGED BY A DOWNWARDLY EXTENDING RECESS ADAPTED TO RECEIVE A PORTION OF SAID SHAFT, AND SAID HEAD PROVIDING HEAD CLEARANCE BETWEEN THE LOCK AND SAID TOP WALL PERMITTING SUCH MOVEMENT OF THE LOCK TOWARD SAID TOP WALL SO AS TO DISPOSE SAID SHAFT IN SAID RECESS. 